i found a bug:

• With this configuration i place protection block as normal by sneak.
  settings:
  prevent-place-everywhere: true
  prevent-destroy-everywhere: false
  sneak-to-place-normal-block: false
  sneak-to-place-field: true

the bug is:
Can place blocks marked as protection by sneak in other player protection field but cannot destroy it, i try to place protected block as normal block.

fixed